Variegated articles of rubber or the like and method of making the same



March 1 1927.

T. J. MELL VARIEGATED ARTICLES OF RUBBER OR THE LIKE .AND METHOD OF MAKING THE SAME 2 Sheets-Sheet 1 7017 JTZEZZ qL l m- Filed Ju1y9, 1925 EMF-i- Patented Mar. 1, 1927.

U NEE PATENT; OFFICE.

TOD J'. MEIiL, OF AKRON, OHIO, ASSIGNOR TO THE B. F. GOODRICH COMPANY, OF NEW I YORK, N. Y., A CORPORATION OF NEW YORK.

VARIEGATED ARTICLES on RUBBER OR THE LIKE AND METHOD or MAKING rm:

SAME.

Application filed July 9, 1925. Serial No. 42,451.

This invention relates to the art of producing variegated articles of plastic material having marbled, mottled or grained color effects, and is of especial value. in the production of rubber sheeting having such color effects. The present invention is an improvetween rolls to produce a single-thicknesssheet, but this procedure is slow and expensive as compared with my method, does notreadily afford so wide a range of color effects, and does not provide so close an imitation of natural marble. I have found that by mixing diflerently colored masses of vulcanizable rubber compounds, sheeting the mixture, preferably between calender rolls, and then splitting or slicing the sheet into thinner sheetsfa very superior imitation of marble, as Well as various other striking color effects may be obtained, and with economyof production, the difference in surface design or appearance apparently being'due to,

the fact that the action of thecalender rolls produces a smearing and thinning'out of the margins of the color zones at the .surface of the sheet which does not occur in the same form within the body of the sheet, Wherefore the splitting of the latter exposes a more clear cut .and pleasing surface design. Diiferent bloom characteristics in the rolled surface and in the cutsurface of the rubber also maybe of some effect in accounting for the different surface appearance "obtained.

Of the accompanying drawings:

Fig. 1 is a perspective View; of parts of av calender and the work therein, showing a preferred form of procedure in accordance with my invention. v

Fig. 2 is a perspective View of the work illustrating different color effects obtained apparatus herein by slicing the relatively thick stock sheet into thinner sheets Fig. 3 is a vertical section of preferred apparatus for ,slicing the stock sheet, and the work therein.

.Different types of mixtures are of course employed according tothe color design desired. I find that one of the more common and popular marble effects may be obtained, for example, by loosely rolling or folding together a light colored sheet of compound 10 and on dark colored sheet 11 as shown in Fig. 1 of the accompanying drawings and feeding the rolled or folded sheets end first through the calender, the rolls of which are shown at 12, 13, 14. The usual liner is shown at 15 for carrying the calendered sheet 16 from the calender.

The calender rolls are so set as to produce a sheet 16 sufficiently thick to be sliced into two or more thinner sheets, 17, 17 Fig. 2, and the sheet 16 preferably is at least partially vulcanized before the slicing operation in order to set it and thus permit it to be.

cut Without permanent distortion or disarrangement of the color elements therein.

cut and progressively release it for passage over the side faces of the knife as the line of cut advances, so as to avoid binding of the knife, as described in my .above'identified copending applications, but I do not wholly limit my claims to the specific procedure or described for slicing the stock sheet. I f

' The preferred apparatus for slicing the stock sheet is shown in Fig. 3, wherein .18, 1 9 are a pair of knurled guiding and pressing rolls, preferably driven at even speed, adapted to feed the stock sheet 16 against a band knife 20 mounted in a knife guide 21. The usual guide plate 22 and means including feed screws such as the screw 23 are provided for slowlyfeeding the knife for- .ward to keep the cutting edge of the knife at the proper position notwithstanding the abrading away of the knife by the usual continuous-sharpening means.

The presser rolls 18, 19 are preferably set i so close together with relation to the nor mal-tliickness of the stock sheet 16 as to reduce the thickness of the sheetat least three per cent as it passes between them, the distance A, from roll to roll, being substantially less than the normal thickness of the sheet, which is indicated by the lines :0, :12, as I find that this facilitates the slicing action of the knife, apparently because it provides in the nip of the rolls a zone of rubber which is virtually rigid with relation to the force of the knife in the plane of the cut, said zone acting somewhat in the manner of a backing plate for the action of the knife, and because it apparently produces a tension in the rubber, in the direction of the thickness of the sheet at the line of cut, a normal cross-seetion of the sheet taking the position indicated by the lines y, 3 because of the volumetric incompressibility of the rubber, so that the cut surfaces do not bear strongly against the faces of the knife with the inward-rolling, friction-increasing effect which occurs when a knife is simply forced against an unrestrained mass of rubber. After the slicing of the sheet the cut surfaces may be smoothed by abrasion or by further vulcanizing the sheet against a surfacing member.

Advantages of my present invention are that the differently colored compounds may be handled in mass, with resulting economy, as distinguished from the use of comminuted material; several sheets of the final product may be obtained from asingle calendered sheet; superior color effects may be obtained as compared with the effect obtained in a rolled surface; the different compounds are so arrayed or interspersed in the final prod not as to provide a strongly laminated sheet; and a wide variation of detail in generally similar designs may be had in successive cuts from the same stock sheet.

ltlodifications may be resorted to, both in the manner of intermingling the compounds and in the slicing of the stock, without departingfroni the scope of my invention as claimed.

I claim.

1. The method of making a variegated rubber article which comprises so mixing together a plurality of masses of rubber of different colors, at least one of the same being plastic, as to produce a mass of chance thereof as a surface of the article.

2.'Th e method of making a Variegated rubber article which comprises mixing together plastic rubber compounds of dlfferent colors, vulcanizing the mixture, and

thereafter removing material from the surface of the resulting mass to expose the in ternal structure thereof as a surface of the article.

3. The method of making variegated rubber sheeting which comprises mixing together plastic rubber compounds of different colors, sheeting the resulting mass by rolling pressure, vulcanizing the. resulting sheet, and thereafter slicing-the resulting sheet into a plurality of thinner sheets.

4. The method of making variegated rubber sheeting which comprises so mixing together a plurality of masses of rubber of different colors, at least one of the same being plastic, as to produce a mass of chance design in details of color arrangement, sheet ing the resulting mass by rolling pressure, subjecting the resulting sheet to vulcanization, and slicing the resulting sheet into a plurality of thinner sheets.

5. An article of manufacture comprising a body of rubber produced by so mixing a plurality of masses of rubber, at least one of the same being in plastic form, as to produce a plastic mass of chance color design, vulcanizing said mass and removing material from the surface thereof to expose its internal structure.

6. Rubber sheeting consisting of a slice taken from a vulcanized mass of rubber comprising a plurality of rubber compounds of difiercnt colors so mixed while at least one of them is in plastic form as to provide a chance color design upon the cut surface of the slice.

7. Rubber sheeting consisting of a slice taken from a vulcanized mass of rubber comprising a plurality of rubber compounds of different colors so mixed while in plastic form as to provide a chance color design upon the cut surface of the slice.

In witness whereof I have hereunto set my hand this 1st day of July, 1925.

TOD J. MELL. 

